https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105681
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Richard Biener from comment #4) > possibly the system header diagnostic changes? Yes, the narrowing check here was PR c++/57891 which was fixed for GCC 9. But it was still allowed in system headers until GCC 12.
